Explosive release actuator



May 31, 1960 J. J. JAGLOWSKI, JR. ET AL EXPLOSIVE RELEASE ACTUATOR INVENTOR.

IRVING SCOTT JOSEPH J. JAGLOWSKI, JR

Filed May 23, 1957 2,938,429 EXPLOSIVE RELEASE ACTUATOR Joseph J. Jaglowski, In, Cornwell Heights, Pa., and Irving Scott, Moorestown, N.J., assignors to the United States of America as represented by the Secretary of the Navy and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to an explosive release unit embodying a disposable release actuator.

Existing release units providing instantaneous and forceful plunger action as required in aircraft bomb racks and shackles utilize an electrically operated solenoid for actuating the plunger. One particular unit uses a plunger with 1.50 inch forward travel and a 60 pound initial and 18 pound final force during the stroke. There are several disadvantages to the device just described, including unreliability under impact and excessive coil delay time. In addition there are failure at low temperatures and inadvertent releases under vibratory conditions.

The present invention overcomes the defects and disadvantages of the aforementioned and similar devices by providing a self-contained cylinder utilizing an explosive charge electrically fired, in which the explosive charge is hermetically sealed in a cartridge retainer with the electric primer. The self-contained cylinder containing the cartridge retainer and the primer forms a subassembly distinct from the remaining structure including the relay and transfer switch, and is disposable or replaceable. This design introduces larger initial and final forces, and reduces the complexity of parts; and, hence, is simpler and cheaper to manufacture.

An object of the present invention is the provision of an explosive release unit of simple construction capable of producing large initial and final forces.

Another object is to provide a positive actuating device which is explosively operated and capable of reliable use over a wide variety of temperature and other physical conditions.

A further object of the invention is the provision of an explosive release unit fired electrically and having a disposable actuating cylinder containing the explosive charge.

The exact nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the annexed drawing in which:

Fig. 1 shows an elevation cross section view of a preferred embodiment of the invention.

Fig. 2 shows a view along section 2--2 of Fig. 1.

Fig. 3 illustrates schematically the electrical wiring diagram for the device of Figs. 1 and 2.

Referring now to the drawing, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in Figs. 1 and 2 the explosive release unit which is constructed of a housing 12 for microswitch 14 and a relay 16, and the disposable or replaceable release actuator 13. Housing 12 may be generally of rectangular cross section with an open top, and along one wall 17 a circular opening 18 and a recess 20 thereabove. A wall 22 separating recess 20 from the interior 21 of housing 12 is provided with 2,938,429 Patented May 31, 1.960

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an opening 24 for the passage therethrough of electrical wires 25 and 26 for a purpose to be explained further below. Microswitch 14 may be mounted in recess 20 by any convenient fashion, such as the bolted brackets 27 illustrated.

' Housing 12 has a removable corner section 28 which forms a part of the circular opening 18, the wall forming the opening 18 is formed with an annular groove 29, for a purpose hereinafter described. Removable section 28 may be kept in place by a pair of bolts 30. Actuator 13 is mounted on housing 12 by inserting the cylindrical support extension 32 into opening 18 with section 28 removed. Extension 32 has an annular raised portion 33 for mating with groove 29. In this manner actuator 13 will be very securely fastened to housing 12 when section 28 is bolted to housing 12.

Disposable release actuator 13 is constructed of a support member 34 which includes extension 32' just described, an inner primer retainer 36, an outer primer retainer 36, a cartridge case 40, a cartridge retainer 42, and a piston sleeve 44.

Support member 34 consists of the support extension 32 described above and has a threaded opening 46 at the opposite end thereof. Inner primer retainer 36 for supporting at one end the electrical primer 48 is threaded at its opposite end and screwed into support member 34. Primer 48 is held clamped into place by the outer primer retainer 38 which is screwed over a male threaded portion 50 of inner primer retainer 36. Both support member 34 and inner primer retainer 36 are provided with a common central passageway 54 for permitting primer lead 56 to pass from primer 48 to relay 16. A disconnect 58 in lead 56 permits ready connection and disconnection of primer 48 when actuator 13 is mounted and dismounted, respectively.

For supporting a supply of the explosive powder 60, cylindrical cartridge case 40, which is open at its left end, is hooked or otherwise clamped at the other end over inner primer retainer 36 as illustrated. For this purpose, case 40 is shaped to closely fit the contours of the inner and outer retainers 36 and 38, and is provided with an annular, inwardly directed lip 62. An 0 ring 64 between lip 62 and a shoulder 66 of inner primer retainer 36 provides sealing against exploding gases at this point. Cartridge retainer 42, having a solid end wall 68, is similarly fitted closely over cartridge case 40 and provided with an annular inwardly directed lip '7 0. Any suitable method of fabricating cartridge retainer 42, case 40, outer primer retainer 38, and inner primer retainer 36 may be utilized, including that of forming the inwardly directed lips 62 and 70 after the assembly is completed. End wall 68 of cartridge retainer 42 is provided with one or more orifices 72 through which the exploding gases pass, as explained further below. The outer periphery of cartridge retainer 42 is provided with a pair of spaced annular grooves 74 and 76 in which are fitted an O ring '78 for sealing purposes and a stop ring 80, respectively. The latter is designed to expand outwardly, but is maintained within its groove by piston sleeve 44.

Fitted closely over cartridge retainer 42 for slidable movement is the cylindrical piston sleeve 44 which has a solid end wall 82 for abutting against wall 68 of retainer 42 when sleeve 44 is in its extreme right position, as illustrated. Adjacent and open opposite end 83 of sleeve 44 there is along the inner surfacethereof an annular groove 84 bounded by an annular tapered shoulder 85 and a transverse shoulder 86.

Extending from the micro-switch 14 is a lever arm 67 pivoted inside thereof and bending at 88 into fiat contact against end 33' of sleeve 44. Sleeve 44 when in its fully mounted position as illustrated in Fig. 1 mainproperly depressed, contact arm 92 of ,in its On position and relay 16 will already have been tains arm 87 and a switch rod 89 abutting against arm 87in a retracted position, which is further described in connection with Fig. 3. f

Fig. 3 illustrates a simplified electrical arrangement for actuating electrical primer 48 in response to the closing of a contact switch 94 by the operator of this device. Micro-switch 14 is connected at pivot contact 90 by a line 91 to a pulse source or energizer 95 forming no part of this invention and which in response to the pilot operated contact switch 94, for example, would pass a pulse to micro-switch 14 to energize unit 10. Micro-switch 14 is provided with a movable contact arm 92 pivoted at 90 for movement'between the On and Off positions shown. In the latters On position, contact is made from line 91 to line 25 connected electrically through line 56 to primer 48 and ground. In the Off position, connection through switch 14 is made comprises a coil 98 connected between ground and line 100 to line 25, and a movable armature 102 on which is mounted the movable contact 104. When relay 16 is unenergized, contact 104 makes electrical connection between line 26 and a line 106. When energized, electrical connection is made between line 100 and a line 108 which leads to line 91 of switch 14. It should be noted that movable contact arm 92 is maintained in its On position by switch rod 89 shown in Fig. 1. When piston sleeve 44 or release actuator 13 is removed, contact arm 92 will return to its normally biased Off position due to the release of lever arm 87.

A standby D.C. supply pressed on the line 91 to when contact arm 92 is in 96 is passed through or immaintain relay 16 energized its On position at the option of the pilot or operator. The pilot or operator adds a pulse on line 91 to fire primer 48 when he presses the switch 94, as is understood in the art. The high energy level necessary to fire the primer 48 is reached only when the pulse -energy-isadded to the DC. electrical energy in the electrical circuit of Fig. 3. g r

The explosive release unit 10 shown in Figs. 1, 2, and 3 operates in the following manner: The pilot or. operator of the aircraft presses a switch (not illustrated) for passing a pulse to line 91 of Fig. 3. If piston sleeve 44 shown in Fig. 1 is properly mounted with lever arm 87 switch 14 will be energized. Then, the pulse is passed to primer 48 for actuationof device 10 as hereinafter' explained. After sleeve 44 is discharged tothe left, contact arm 92 returns to its normally biased Off position, making a continuous contact through relay 16 and line 106 to the next rack of bombs. A subsequent'pulsing by the pilot or operator will cause actuation of a similar unit 10 in the next rack. When primer 48 is energized as just described, referring to Fig. 1, explosive powder 60 within cartridge case 40 explodes and gives off a large volume of combustion gases, as is understood in the art. These gases pass through orifices 72 and act against wall 82 of piston sleeve 44 to force the latter to move to the left as indicated by arrow A. rings 78 and 64, as noted previously, provide sealing against gas leaks. When sleeve 44 reaches a position where the angular shoulder 85 comes adjacent annular slot 76 in cartridge retainer 42, stop ring 80 in slot 76 expands into annular groove 84 and abuts the transverse shoulder 86 to stop further travel of sleeve 44. In this manner, sleeve 44 is re tained on release unit after actuation is complete. The outer surface 83' of wall 82 may be shaped in any desired fashion to cause the type of contact with another member (not illustrated) as may be required.

In order to prepare unit 10 for further use, release actuator 13 may be quickly removed by releasing disconnect to a line 26. Relay 16 58, unscrewing bolts 30, removing section 28, and ex tracting support extension 32 from opening 18. Anothe actuator, prepared in advance, is inserted in hole 18 i the same manner, and reengaging disconnect 58 again. 1 There has thus been provided an explosive release device which is relatively simple in design and yet very reliable in service, especially under adverse conditions of temperature and vibration, by not being subject to inadvertent release even under the most 'severe vibratory or acceleration conditions. Also, the device is capable of bringing to bear very high forces over the whole trave length of sleeve 44, far in excess of anything that can be produced by an electrically operated solenoid device of the same size. Further, the device is completely devoid of costly and troublesome arrangements involving close tolerances and relationships.- The utility of the device is further enhanced by the design feature which permits instant re-arming' by merely replacing a dissipated actuator with a charged one prepared in advance.

It should be understood of course that the foregoingv f disclosure relates to only a preferred embodiment of the invention and that numerous modifications or altera- 1 tions may be made therein without departing from the spirit and the scope of the invention as set forth in the 1 appended claims. What is claimed is: l

1. An explosive release device tion, a casing, a support member releasably mounted on said casing, hollow cartridge means supported at one end by said support member and forming an open-ended powder chamber, gas generating means in said powder chamber, a hollow cartridge retainer fixedly mounted on said hollow cartridge means for enclosing said powder chamber and having anend wall with orifices extending therethrough, hollow piston means enclosing and slidably disposed on said hollow retainer and having an end Wall adjacent said retainer end wall, said gas generating means adapted to expand gas through said orifices and cause movement of said hollow piston means, means for preventing said hollow piston means from sliding completely off said hollow cartridge retainer in response to the urging action of said gas, andmechanical interlock means disposed between said hollow pistonmeans and said casing and permitting actuation of said gas generating means only when said hollow piston means is in a proper position on said hollow cartridge retainer, and said mechanical interlock means comprising lever arm means carried by said casing and having one end extending therefromin such a manner as to be depressed by said hollow piston means when the latter is in said proper position on said hollow cartridge retainer.

2'. An explosive release device as set forth in claim 1, wherein said mechanical interlock means further comcomprising, in combinal prises 'a normally open microswitch connected to said casing and adapted to be operated by said lever arm means. a

3. An explosive release device as set forth in claim 2, wherein said lever arm means comprises a lever arm having one end connected to said microswitch and the other end adapted to be engaged by the inner end of said hollow piston means, and a switch rod adapted to close said microswitch when said lever arm is depressed by. said hollow piston means.

References Cited in the file of this patent 7 UNITED STATES PATENTS 1,336,656 Rogozea Apr. 13, I920 1,569,153 Temple Jan. 12, 1926 1,713,906 Lake May 21, 1929 2,309,978 Iratt Feb. 2, 1943 2,337,647 Caulkins Dec. 28, 1943 2,469,400 Newell May 10, 1949 

